French played a major, though not the only role, in the pervasive multilingualism of British history and culture. As Britain’s only medieval ‘global’ vernacular, it was also important to a wide range of people for their participation in external theatres of empire, trade, culture, conflict, and crusade. Displacing the long shadow of nineteenth-century nationalizing conceptions of language and their entrenchment in modern university disciplinary divisions, emerging histories of French in England and increasingly of French in Ireland, Wales, and Scotland offer new ways of understanding language and identity. These lectures trace francophone medieval Britain in a chronological sequence across its four main centuries, interpolating two thematic lectures on areas especially needing integration into our histories, medieval women and French in Britain, and French Bible translation in medieval England.